Problem: $\dfrac{2}{8} + \dfrac{7}{5} = {?}$
$ = {\dfrac{2 \times 5}{8 \times 5}} + {\dfrac{7 \times 8}{5 \times 8}} $ $ = {\dfrac{10}{40}} + {\dfrac{56}{40}} $ $ = \dfrac{{10} + {56}}{40} $ $ = \dfrac{66}{40}$